The present invention relates to electronic components, solid electrolytic capacitors, and circuit substrates mounted with the same, more specifically, to an electronic component having a current breaking function, a solid electrolytic capacitor having a current breaking function, and a circuit substrate including such a solid electrolytic capacitor.
In recent years, as progress is being made in miniaturization of electronic devices such as portable information terminals, miniaturization and safety is required for the various types of electronic components forming the circuit of an electronic device.
Among such electronic components, in various types of portable information terminals, such as a personal computers and mobile phones, various types of video information devices such as digital cameras, and other types of electronic devices, solid electrolytic capacitors are particularly often incorporated in the power supply circuit of a CPU and its peripheral circuits. A solid electrolytic capacitor is advantageous in that it has a low failure rate.
Japanese Laid-Open Patent Publication No. 2001-176374 describes a so-called fuse-incorporated solid electrolytic capacitor in which a fuse is connected between a capacitor element and a terminal. The fuse is sealed in a package resin.
In the fuse-incorporated solid electrolytic capacitor described in the above publication, the fuse (i.e., wire-like sintered fuse that melts at a temperature of approximately 300° C.) is installed between the capacitor element and the terminal. The fuse opens the electric circuit and breaks the flow of current when excessive short-circuit current flows to the capacitor element.
However, when using the fuse-incorporated solid electrolytic capacitor described in the above publication, the structure becomes complicated, and the volume efficiency of the internal elements is decreased by an amount corresponding to the space occupied by the fuse. Thus, there is a certain limit when reducing the solid electrolytic capacitor in size while increasing the capability of the solid electrolytic capacitor. Such a limit to miniaturization resulting from the addition of the fuse applies not only to solid electrolytic capacitors but also to various types of electronic components used in electronic devices.